The capabilities of electronic telecommunication networks have expanded dramatically in recent years. The recent advances in telecommunication network technology are due in part to the increasing use of fiber optics as a data transmission medium in such networks. This has enabled transmission of data throughout the network at higher data rates--i.e. the product of the quantity and velocity of data carried through the network--than had heretofore been possible. Data rates of 100 Megabits per second (100 Mbs/sec) are now readily achievable whereas, before the advent of fiber optic transmission lines, data rates of 10 Mbs/sec were more typical. As a result, networks may utilize more advanced peripherals--such for example as the keyboard and video screen of a computer terminal, or a telephone--and other data processing devices which are more versatile and respond to or communicate a user's instructions at greater speeds.
Accordingly, it is desirable to use fiber optics as the data transmission medium in telecommunication networks to the greatest extent possible. One advantageous application of fiber optic telecommunication cable is the routing of signals or information between buildings--such for example as office buildings, retail establishments, warehouses, laboratories, manufacturing facilities and private homes--in which peripherals or other data processing devices are situated for data transmission between the data processing devices in the various buildings.
Fiber optic telecommunication cable normally cannot be connected directly to peripherals or other data processing devices unable to receive, process or output the optical signals carried by the fiber optics. The peripherals and other data processing devices usually receive and emit electrical signals via an electrical telecommunication cable. Thus, at least one converter--referred to herein as a "photo transceiver"--for transforming or converting an optical signal to an electrical signal, and vice versa, is usually provided at each junction between a fiber optic telecommunication cable and an electrical telecommunication cable which is, in turn, connected to at least one peripheral or other data processing device.
It is often preferable for the fiber optic cable to extend to a wiring closet in the building for connection to a photo transceiver situated therein. Branches defined by respective electrical telecommunication cables extend from the photo transceiver to the one or more peripherals or other data processing devices located in the building. A plurality of peripherals or other data processing devices may therefore use the same photo transceiver, thus limiting the required number of such transceivers which are typically expensive.
If a building has previously been wired with electrical telecommunication cable for peripherals or other data processing devices, such existing cable is preferably connected to a photo transceiver in a wiring closet within the building for connection to a fiber optic cable. The fiber optic cable may thus be connected to the peripherals or other data processing devices without having to install new electrical cable in, and to possibly remove the existing cable from, the building. Such an installation, whether or not in conjunction with the removal of existing cable, is normally a substantial undertaking since communications cables are typically routed through walls, floors, and ceilings and the like.
Whether or not previously installed, the electrical telecommunication cable routed throughout a building will ordinarily require electrical connectors to connect one end of the electrical cable to a respective peripheral or other data processing device and the opposite end of the cable to the photo transceiver. A conventional modular electrical connector may have a jack assembly including a printed circuit wiring board or substrate and is ordinarily mounted on an interior wall surface of the building. An electrical telecommunication cable may be fixedly connected to the jack assembly and extend into the interior of the wall, eventually terminating at another jack assembly to which the cable is also fixedly connected. The second jack assembly is typically mounted on another interior wall surface proximate the photo transceiver.
The jack assembly proximate the photo transceiver may receive a matching plug connected, in turn, to the transceiver. The other jack assembly may receive a matching plug connected to a peripheral or other data processing device which is thereby connected, via the electrical telecommunication cable and the electrical connectors, to the photo transceiver.
Unfortunately, undistorted data transmission through such electrical cables has proven difficult because of crosstalk produced within the electrical connectors. Such distortion is caused by electromagnetic fields that are created by current flow through the conductors within the connector and which cause electromagnetic coupling between the conductors. This electromagnetic coupling is amplified by the higher data rates made possible by the fiber optics--as for example 100 Mbs/sec--at which such crosstalk becomes unacceptable.
The crosstalk produced in conventional modular jack assemblies may be mitigated by lowering the data transfer rate therethrough. Such a procedure, however, diminishes or sacrifices major benefits--as for example the use of advanced peripherals and other data processing devices--made possible by the use of fiber optics. It is therefore desirable to maintain the increased data rate.
It is also desirable to limit or minimize changes to the structure of existing modular connector assemblies so as to allow continued use of the existing manufacturing capacity for the unchanged parts or components. It is further desirable for those components of the connector assemblies which physically interface or mate with other components of the telecommunication network--as, for example, the matching plugs that are connected to the peripherals and other data processing devices--to not be altered so that no changes to such other components of the network will be necessary.